Datasheet

LM555
SNAS548B –MAY 2004–REVISED JULY 2006 www.ti.com
V
CC
= 5V Top Trace: Modulation 1V/Div.
TIME = 0.2 ms/DIV. Bottom Trace: Output Voltage 2V/Div.
R
A
= 9.1kΩ
C = 0.01μF
Figure 10. Pulse Width Modulator
PULSE POSITION MODULATOR
This application uses the timer connected for astable operation, as in Figure 11, with a modulating signal again
applied to the control voltage terminal. The pulse position varies with the modulating signal, since the threshold
voltage and hence the time delay is varied. Figure 12 shows the waveforms generated for a triangle wave
modulation signal.
Figure 11. Pulse Position Modulator
V
CC
= 5V Top Trace: Modulation Input 1V/Div.
TIME = 0.1 ms/DIV. Bottom Trace: Output 2V/Div.
R
A
= 3.9kΩ
R
B
= 3kΩ
C = 0.01μF
Figure 12. Pulse Position Modulator
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